Wow, sis, welcome to my world.
I, too, prefer lrf > lrx > ePub. Epub is last only when it is poorly made. I hate when the font size is enlarged and you end up with big empty space margins and only 3 or 4 words per line. My other gripe is that not all publishers take the time to convert from a good beginning source to get a nice looking ePub. So, not all ePubs look the same or even have the same font size. I always try the ePub first and if I don't like it, I use whatever else is available to try for my 505. I wish I knew how to do my own "tweeking" to get nice looking books.
Some of the nonDRM ePubs look beautiful. Try
Zelda's, "Three Men in a Boat" and pdurrant's published
"Desbarollda, The Waltzing Mouse" (for purchase,
but he will send you HIS ePub version if you have bought the book)
My understanding (from reading some posts by Adobe and MR members) is that the rendering of ePub is in transition. So the look of ePub on the Sony is a software problem and will need the update. Supposedly, it will be available to all Companies sometime in 2010. (Some threads that have information on ePub that is useful to know for 505 owners also):
The new ePub DRM
Why is it good that Sony went epub?